In the conventional Passive Optical Network (PON)-based mobile bearer network, as shown in FIG. 1, a PON is adopted for mobile bearer on various types of services from a Base Station (BS). The BS may be a Base Transceiver Station (BTS) of a 2nd generation (2G) mobile network, where the BTS accesses the PON through E1/T1 Time Division Multiplexing (TDM); the BS may be a NodeB of a 3rd generation (3G) mobile network, where the NodeB accesses the PON through Asynchronous Transfer Mode (ATM)/Inverse Multiplexing over ATM (IMA); and the BS may also be an eNodeB of a Long Term Evolution (LTE) mobile network, where the eNodeB accesses the PON through a Fast Ethernet (FE)/Gigabit Ethernet (GE). Afterwards, the PON is connected to a aggregate gateway through a metropolitan-area convergence network, and the aggregate gateway is further connected to a mobile network element, for example, a Base Station Controller (BSC) of the 2G mobile network, a Radio Network Controller (RNC) of the 3G mobile network, or an Access Gateway (AGW) of the LTE mobile network. The metro convergence network is usually a Packet Switched Network (PSN) implemented through a Multi-Protocol Label Switching (MPLS) technology.
For a Gigabit Passive Optical Network (GPON) and a next generation GPON, a PON logical service transmission channel is a GPON Encapsulation Method (GEM) port, and is identified by using a GEM port identifier (ID). For an Ethernet Passive Optical Network (EPON) and a next generation EPON, the PON logical service transmission channel is a Logical Link Identifier (LLID) channel, and is identified by using an LLID.
For the conventional PON-based mobile bearer network, a convergence node is required to have various types of interfaces (for example, an ATM interface, an E1/T1 interface, a Synchronous Digital Hierarchy (SDH) interface, and an FE/GE interface) to support various types of service. Further, both an Optical Line Terminal (OLT) and an Optical Network Unit (ONU) of the existing PON-based mobile bearer network need to perceive ATM/IMA, E1/T1 TDM, and ETH services. As a result, the implementation is complex. The inventor finds that a major problem needs to be solved about how ATM/IMA service, E1/T1 TDM service, Ethernet (ETH) service, or Internet Protocol (IP) service can be carried over an aggregation node, i.e., Provider Edge (PE).